Ingston General Hospital (Kingston, Ontario). Fasted Title Loaded From File Insulin levels were determined with a commercially available enzyme-linked immunoabsorbent assay (ELISA) kit (ALPCO Diagnostics, Salem, NH). All samples were run in duplicate, with the CV being ,10 for all values. Insulin sensitivity was estimated using homeostatic model assessment ?insulin resistance (HOMA-IR) with the equation: HOMA-IR = [fasting insulin (mIU/mL)6fasting blood glucose (mmol/L)]/22.5. Plasma interleukin-6 (IL-6), tumor necrosis factor alpha (TNFa), and adiponectin were determined using commercially available high sensitivity ELISA kits (R D Systems, Minneapolis, MN). All samples from individual participants were tested in duplicate on the same assay plate. Repeat analysis was performed on duplicates that varied by more than 15 and the average of all repeats was used for analyses. Values are reported in pg/mL (IL-6, TNFa) and ng/mL (adiponectin).Post-training MeasuresPost-training tests were conducted in an identical manner as the baseline measures. Fasted blood and a resting muscle biopsy were sampled 72 h following the final training session. 48 h after the muscle biopsy, participants performed an incremental VO2peak ramp protocol, then a 500 kcal time to completion trial 24 h later. Participants were also asked about how much they enjoyed the exercise they engaged in as well as their confidence to continue to engage in it. Perceived enjoyment was assessed by the question “How enjoyable would it be for you to do high intensity interval training 3 days per week?” Responses were recorded on a scale of 1 23148522 (not enjoyable at all) to 7 (extremely enjoyable). Scheduling selfefficacy was assessed using a single item measure of confidence “How confident are you that you could schedule interval training sessions three times per week?” and task self-efficacy was assessed using the single item measure “How confident are you that you would complete interval training sessions three times per week?” Both self-efficacy questions utilized a 10-point Likert scale ranging from 1 (not confident at all) to 10 (completely confident). Intentions to implement high intensity exercise following completion of the study was assessed by asking participants “at the completion of this study, I intend to add hard, or very hard exercise of at least 30 minutes to my leisure time physical activity”, with items being “at least once per week”, “three times per week”, and “five times per week”. Intention to implement questions utilized a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree).StatisticsA two-way, repeated measure ANOVA was used to compare the effects of time (training status) and interval intensity (group). Data analysis was completed with GraphPad Prism v 5.01 (GraphPad Software, Inc., La Jolla, CA). Statistical significance was accepted at p,0.05 unless otherwise noted.Results Muscle Oxidative CapacityA main effect of training (p,0.01; Figure 1A) was observed for both COX I (LO, (-)-Calyculin A biological activity Pre-test: 160.09 Arbitrary Units (AU), Post-test: 1.0860.09 AU; HI, Pre-test: 160.06 AU, Post-test: 1.1960.10 AU) and COX IV (LO, Pre-test: 160.13 AU, Posttest: 1.1760.13 AU; HI, Pre-test: 160.07 AU, Post-test: 1.1860.10 AU) protein content (see representative blots, Figure 1B). Maximal activity of CS increased in both the LO (Pre-test: 43.864.7 mmol/min/g, Post-test: 47.265.1 mmol/min/ g) and HI (Pre-test: 43.664.5 mmol/min/g, Post-test: 49.968.8 mmol/min/g) groups resul.Ingston General Hospital (Kingston, Ontario). Fasted insulin levels were determined with a commercially available enzyme-linked immunoabsorbent assay (ELISA) kit (ALPCO Diagnostics, Salem, NH). All samples were run in duplicate, with the CV being ,10 for all values. Insulin sensitivity was estimated using homeostatic model assessment ?insulin resistance (HOMA-IR) with the equation: HOMA-IR = [fasting insulin (mIU/mL)6fasting blood glucose (mmol/L)]/22.5. Plasma interleukin-6 (IL-6), tumor necrosis factor alpha (TNFa), and adiponectin were determined using commercially available high sensitivity ELISA kits (R D Systems, Minneapolis, MN). All samples from individual participants were tested in duplicate on the same assay plate. Repeat analysis was performed on duplicates that varied by more than 15 and the average of all repeats was used for analyses. Values are reported in pg/mL (IL-6, TNFa) and ng/mL (adiponectin).Post-training MeasuresPost-training tests were conducted in an identical manner as the baseline measures. Fasted blood and a resting muscle biopsy were sampled 72 h following the final training session. 48 h after the muscle biopsy, participants performed an incremental VO2peak ramp protocol, then a 500 kcal time to completion trial 24 h later. Participants were also asked about how much they enjoyed the exercise they engaged in as well as their confidence to continue to engage in it. Perceived enjoyment was assessed by the question “How enjoyable would it be for you to do high intensity interval training 3 days per week?” Responses were recorded on a scale of 1 23148522 (not enjoyable at all) to 7 (extremely enjoyable). Scheduling selfefficacy was assessed using a single item measure of confidence “How confident are you that you could schedule interval training sessions three times per week?” and task self-efficacy was assessed using the single item measure “How confident are you that you would complete interval training sessions three times per week?” Both self-efficacy questions utilized a 10-point Likert scale ranging from 1 (not confident at all) to 10 (completely confident). Intentions to implement high intensity exercise following completion of the study was assessed by asking participants “at the completion of this study, I intend to add hard, or very hard exercise of at least 30 minutes to my leisure time physical activity”, with items being “at least once per week”, “three times per week”, and “five times per week”. Intention to implement questions utilized a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree).StatisticsA two-way, repeated measure ANOVA was used to compare the effects of time (training status) and interval intensity (group). Data analysis was completed with GraphPad Prism v 5.01 (GraphPad Software, Inc., La Jolla, CA). Statistical significance was accepted at p,0.05 unless otherwise noted.Results Muscle Oxidative CapacityA main effect of training (p,0.01; Figure 1A) was observed for both COX I (LO, Pre-test: 160.09 Arbitrary Units (AU), Post-test: 1.0860.09 AU; HI, Pre-test: 160.06 AU, Post-test: 1.1960.10 AU) and COX IV (LO, Pre-test: 160.13 AU, Posttest: 1.1760.13 AU; HI, Pre-test: 160.07 AU, Post-test: 1.1860.10 AU) protein content (see representative blots, Figure 1B). Maximal activity of CS increased in both the LO (Pre-test: 43.864.7 mmol/min/g, Post-test: 47.265.1 mmol/min/ g) and HI (Pre-test: 43.664.5 mmol/min/g, Post-test: 49.968.8 mmol/min/g) groups resul.
